Inflammatory bowel disease (IBD), which occurs world-wide and afflicts millions of people, is the collective term used to describe three gastrointestinal disorders of unknown etiology: Crohn's disease (CD), ulcerative colitis (UC), and indeterminate colitis (IC). IBD, together with irritable bowel syndrome (IBS), will affect one-half of all Americans during their lifetime, at a cost of greater than $2.6 billion dollars for IBD and greater than $8 billion dollars for IBS. A primary determinant of these high medical costs is the difficulty of diagnosing digestive diseases and how these diseases will progress. The cost of IBD and IBS is compounded by lost productivity, with people suffering from these disorders missing at least 8 more days of work annually than the national average.
Inflammatory bowel disease has many symptoms in common with irritable bowel syndrome, including abdominal pain, chronic diarrhea, weight loss, and cramping, making definitive diagnosis extremely difficult. Of the 5 million people suspected of suffering from IBD in the United States, only 1 million are diagnosed as having IBD. The difficulty in differentially diagnosing IBD and determining its outcome hampers early and effective treatment of these diseases. Thus, there is a need for rapid and sensitive testing methods for determining IBD and its subtypes.
Over the years, little progress has been made in precisely diagnosing clinical subtypes of IBD. Thus, there is an urgent need for improved methods for diagnosing an individual with IBD, and determining the subtype, such as Crohn's Disease (CD) or ulcerative colitis. Since 70% of CD patients will ultimately need a GI surgical operation, the ability to diagnose those patients early in their disease state to mitigate unnecessary surgery in the future is important. The present invention satisfies these needs and provides related advantages as well.